U.S. Pat. No. 5,116,385, issued on May 26, 1992 in the name of the present single applicant and designating two (dr Paul ALLARD and dr Jean DANSEREAU) of the four present joint inventors, discloses a prosthetic foot keel provided with means for enhancing medio-lateral stability during gait of the amputee. These means were embodied in an inward, medio-lateral forefoot portion extension of the prosthetic keel which, by extending the lever arm of the deformable keel, produced a medio-lateral propulsion capability at foot push off.
U.S. Pat. No. 4,395,783 issued 2 Aug. 1983 to the british company Vessa limited, discloses a conventional artificial leg with an endoskeletal type ankle attachment member. The shin member 12 (FIG. 1) is fitted with a prosthetic foot consisting of a relatively rigid, elastomeric-covered keel 41. The ankle base 42 is secured at its upper face to an ankle attachment member 38 and at its lower face to the keel 41 about a transverse (generally horizontal) ankle pivot 43. Bolt 24 engages (generally vertically, i.e. axially of the limb ) in the insert 39, to secure the ankle base 42 to the ankle attachment member 38.
U.S. Pat. No. 5,156,632 issued 20 Oct. 1992 to the german corporation Otto Bock Ortho dische Industrie Besitzund Verwaltungs-Kommanditgesellschaft, Industriestra.beta.e discloses another prosthetic foot, with artificial leg with another endoskeletal type, ankle attachment member, but with the prosthetic foot now being jointless. The stub-like foot adapter, 3, (with a semi-spherical upper surface) is for detachable connection to the overlying prosthetic limb.
U.S. Pat. No. 4,413,360 issued Nov. 8, 1983 to Steve LAMB and Larry LAMOREUX, discloses an ankle assembly for a prosthetic foot, being provided with means for heel height adjustment and heel securing in an optimum position for comfort of the amputee. A mechanism is interposed between an ankle block and a connected foot block with a pivot and associated adjustment screw for altering the fore and aft tilt of the foot block with respect to the ankle block. More specifically, screws 58, actuated by an Allen key, operate on a tilting casing 46, so as to be able to precisely adjust the orientation of the keel relative to the antero-posterior plane of the limb.